John Apple brought this to my attention, and I want to pass it on to you. The North Universalist Chapel Society houses this important organ, and this page of their website explains the detail and restoration. Since we have restored all of the Thayer sonatas and many of his other pieces, this organ and its restoration was naturally of interest. It’s not a long story, and I believe you will enjoy it.
Founding members of the Organ Historical Society, E. A. Boadway and Robert Reich “discovered” it in 1956. Having been aware that once prominent Boston organist, W. Eugene Thayer (1838—1889), once owned an organ, it was a small matter to match the names on the stop knobs with the stop names published by Thayer in a journal entitled The Organists’ Journal & Review. Thayer was a colorful and influential character in Boston’s organ scene, so finding an organ carefully specified by him indicated a direct link with the thinking of the times.